NICOSIA: At least two more civilians were killed in Syria on Thursday, activists said, as the Arab League prepared to meet to discuss measures against Damascus over its bloody crackdown on dissent.

The Syrian Observatory for Human Rights said a sniper killed a man in the Bayyada area of the flashpoint central city of Homs, where security forces shot dead another civilian during a raid in Karm el-Zeitoun district.

It said heavy machinegun fire blasted the city of Rastan following a one-hour clash early on Thursday between soldiers and army defectors.

On Tuesday, six children and five mutinous soldiers were among 34 people killed across Syria, according to the Britain-based group.

Ahead of the Arab League meeting in the Egyptian capital, Lebanon's Foreign Minister Adnan Mansur said Beirut would not endorse any potential sanctions against Syria.

"Lebanon will not endorse any sanctions by the Arab League against Syria," Mansur, who is backed by the Shiite militant group Hezbollah which is supported by Damascus and Tehran, said before heading to Cairo.

Lebanon voted against when Damascus was suspended from the 22-member Arab League earlier this month, siding with Yemen and Syria, as pressure mounts on the regime of President Bashar al-Assad to end its bloody crackdown on dissent.

The United Nations says the conflict in Syria has claimed more than 3,500 lives, mostly civilians, since it broke out in mid-March.